Are you using the form dated 04/2009 as the guidance notes and form are very clear compared to others I have seen...The only mention of photocopies is where it says 'documents must be originals and copies of any type are not acceptable'.
We didnt even submit photocopies with our Settlement visa application. The thing was big enough as it was.
http://www.ukba.homeoffice.gov.uk/ukresidency/extendingyourstay/applicationtype/flr(m)/